I am trying to plan an engine build plan, and i want to hear any SERIOUS experience and advice on the topic.I am about to build a forced inducted race engine and I want to stay in the 4A family ! I am looking for going up to 250-300 whp.I am currently thinking of the following plans:

I feel that with Time Attack, and the HP numbers you're shooting for, the original rear diff/axles do not have the strength to hold up to the torque you'll be putting through them. There are usually some chicanes and other places that if you're driving competitively and hard, and transitioning from side to side, place a sudden load on axles that will snap them like toothpicks. Not sure if this is something that Spence Weir can help with, but it might be worth giving him a shout. Also, with that much power in this light of a car, you are going to need some serious tire, which will put even more stress on the axles. plus you'll need some great brakes and a way to cool them.

I also feel that getting 250-300whp out of a 1.6L, even though easily achievable, will NOT be very reliable unless you are spending boatloads of money, and are absolutely meticulous with your assembly and maintenance. For this kind of power, I would say get the absolute strongest block and crank you can find, and use aftermarket rods and pistons. This might be worth higher static compression than normal on an FI engine, with perhaps o-ringing the cylinders to help with the higher cylinder pressures. MIght also be worth looking into water/meth injection if allowed and probably a sprayer on the FMIC. It'll be a fine line getting a cam that will work nicely with the boosted engine, shorter duration with higher lift, which might require solid lifter buckets (yaris) and cleaning the head to make sure there's clearance for the cams. I personally would stay with 16v, because of the parts availability.

Those are my thoughts, for what they're worth; I wish you luck on this endeavor.

Go with OEM 4AGZE head,Block, Crank, Rods and pistons std. Or 0.5 OS you be able to put down 250hp with ARP all bolts!! It will hold just don't over boost it

For Turbo step up, there is not bolt on kit, everything will have to be hand picked part by part,

In the end, what do you want , a sick one off motor build crazy HP get only a couple laps, then it breaks and you spend all your timetrying to fix your problem at the track and watch other ppl enjoy there cars Because you have motor problems lol OR a reliable Motor with good power you can Drive event after event with no to minor problems

I know which one I'll choose any day.

Last edited by mad_86 on Wed Apr 12, 2017 3:09 pm, edited 1 time in total.

hachirokkos wrote:i dont really have a specific budget, cz it will not be built in a month. will be a long term project, so .....

Are you going to be using pump gas or any type of racing fuel?

I am thinking of pump gas with race fuel additive

If you're really willing to spend a bunch of money then you might want to talk to yoshimitsuspeed.Or visit his website http://www.matrixgarage.com/He can give you really great advice on what you're planning to do with your build.

But if you don't want to spend too much money.Getting a 4agze would be good enough. Remove the SC, get a good turbo, 550cc injectors, walbro fuel pump. Don't buy those cheap ebay exhaust manifolds, they're crap. Buy a good one or let someone fabricate one for your car. A aftermarket ecu of your choice. Should get you at 250hp. Maybe more. 4agze blocks can handle it. If you're going to use race fuel additive remember to always keep using it if you dyno'd the car with it. Or you might damage the pistons. Some people dyno their car on race fuel then fill it up with normal gas and expect it to run the same. It doesn't.